#include <bits/stdc++.h> using namespace std; int main() { int n,k,p; cin >> n >> k >> p; if(n == 1 && k == 1) { cout << 0; return 0; } int t[n]; for(int i=0;i<n;i++) t[i] = i+1; int exist[n]; int res = 0; do{ for(int i=0;i<n;i++) exist[i] = 1; for(int i=0;i<k;i++) { int a = -1; for(int j=0;j<n;j++) { if(!exist[j]) continue; if(a >=0 && t[a] > t[j]) exist[j] = 0; if(a >=0 && t[a] < t[j]) exist[a] = 0; a = j; } // cout << i << ": " << "# " << zlicz << "\n"; int zlicz = 0; for(int j=0;j<n;j++) if(exist[j]) zlicz ++; if(zlicz == 1) { if(i < k-1) break; else { res++; if(res > 2000000000) res = res % p; } } } } while(next_permutation(t,t+n)); res = res % p; cout << res; return 0; } //cout << "# " << zlicz << "\n"; /* for(int i=0;i<n;i++) cout << t[i] << " "; cout << "\n"; */
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 | #include <bits/stdc++.h> using namespace std; int main() { int n,k,p; cin >> n >> k >> p; if(n == 1 && k == 1) { cout << 0; return 0; } int t[n]; for(int i=0;i<n;i++) t[i] = i+1; int exist[n]; int res = 0; do{ for(int i=0;i<n;i++) exist[i] = 1; for(int i=0;i<k;i++) { int a = -1; for(int j=0;j<n;j++) { if(!exist[j]) continue; if(a >=0 && t[a] > t[j]) exist[j] = 0; if(a >=0 && t[a] < t[j]) exist[a] = 0; a = j; } // cout << i << ": " << "# " << zlicz << "\n"; int zlicz = 0; for(int j=0;j<n;j++) if(exist[j]) zlicz ++; if(zlicz == 1) { if(i < k-1) break; else { res++; if(res > 2000000000) res = res % p; } } } } while(next_permutation(t,t+n)); res = res % p; cout << res; return 0; } //cout << "# " << zlicz << "\n"; /* for(int i=0;i<n;i++) cout << t[i] << " "; cout << "\n"; */ |